Java文件下载的几种方式[下载]

所属分类：[网络编程] | 创建时间：2013-01-13 | 文章属性：原创 | 文章来源：http://windfly.cn | 作者：windfly

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 Java&#25991;&#20214;&#19979;&#36733;&#30340;&#20960;&#31181;&#26041;&#24335;
 
 
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 <pre name="code" class="java">public HttpServletResponse download(String path, HttpServletResponse response) {
 try {
 // path&#26159;&#25351;&#27442;&#19979;&#36733;&#30340;&#25991;&#20214;&#30340;&#36335;&#24452;&#12290;
 File file = new File(path);
 // &#21462;&#24471;&#25991;&#20214;&#21517;&#12290;
 String filename = file.getName();
 // &#21462;&#24471;&#25991;&#20214;&#30340;&#21518;&#32512;&#21517;&#12290;
 String ext = filename.substring(filename.lastIndexOf(&quot;.&quot;) + 1).toUpperCase();
 
 // &#20197;&#27969;&#30340;&#24418;&#24335;&#19979;&#36733;&#25991;&#20214;&#12290;
 InputStream fis = new BufferedInputStream(new FileInputStream(path));
 byte[] buffer = new byte[fis.available()];
 fis.read(buffer);
 fis.close();
 // &#28165;&#31354;response
 response.reset();
 // &#35774;&#32622;response&#30340;Header
 response.addHeader(&quot;Content-Disposition&quot;, &quot;attachment;filename=&quot; + new String(filename.getBytes()));
 response.addHeader(&quot;Content-Length&quot;, &quot;&quot; + file.length());
 OutputStream toClient = new BufferedOutputStream(response.getOutputStream());
 response.setContentType(&quot;application/octet-stream&quot;);
 toClient.write(buffer);
 toClient.flush();
 toClient.close();
 } catch (IOException ex) {
 ex.printStackTrace();
 }
 return response;
 }&#160;</pre>
 
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 <pre name="code" class="java">public void downloadNet(HttpServletResponse response) throws MalformedURLException {// &#19979;&#36733;&#32593;&#32476;&#25991;&#20214;
 int bytesum = 0;
 int byteread = 0;
 
 URL url = new URL(&quot;windine.blogdriver.com/logo.gif&quot;);
 
 try {
 URLConnection conn = url.openConnection();
 InputStream inStream = conn.getInputStream();
 FileOutputStream fs = new FileOutputStream(&quot;c:/abc.gif&quot;);
 
 byte[] buffer = new byte[1204];
 int length;
 while ((byteread = inStream.read(buffer)) != -1) {
 bytesum += byteread;
 System.out.println(bytesum);
 fs.write(buffer, 0, byteread);
 }
 } catch (FileNotFoundException e) {
 e.printStackTrace();
 } catch (IOException e) {
 e.printStackTrace();
 }
 }&#160;</pre>
 
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 <pre name="code" class="java"> 
//&#25903;&#25345;&#22312;&#32447;&#25171;&#24320;&#25991;&#20214;&#30340;&#19968;&#31181;&#26041;&#24335;
 public void downLoad(String filePath, HttpServletResponse response, boolean isOnLine) throws Exception {
 File f = new File(filePath);
 if (!f.exists()) {
 response.sendError(404, &quot;File not found!&quot;);
 return;
 }
 BufferedInputStream br = new BufferedInputStream(new FileInputStream(f));
 byte[] buf = new byte[1024];
 int len = 0;
 
 response.reset(); // &#38750;&#24120;&#37325;&#35201;
 if (isOnLine) { // &#22312;&#32447;&#25171;&#24320;&#26041;&#24335;
 URL u = new URL(&quot;file:///&quot; + filePath);
 response.setContentType(u.openConnection().getContentType());
 response.setHeader(&quot;Content-Disposition&quot;, &quot;inline; filename=&quot; + f.getName());
 // &#25991;&#20214;&#21517;&#24212;&#35813;&#32534;&#30721;&#25104;UTF-8
 } else { // &#32431;&#19979;&#36733;&#26041;&#24335;
 response.setContentType(&quot;application/x-msdownload&quot;);
 response.setHeader(&quot;Content-Disposition&quot;, &quot;attachment; filename=&quot; + f.getName());
 }
 OutputStream out = response.getOutputStream();
 while ((len = br.read(buf)) &gt; 0)
 out.write(buf, 0, len);
 br.close();
 out.close();
 }</pre>
 
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